Knowledge Base › Troubleshooting Atlas › Embedding
Air bubbles trapped in the paraffin block
What it looks like
Air bubbles appear as small, round voids within the paraffin block, potentially affecting tissue morphology on the slide.
Where it usually appears: Typically seen during the embedding process, particularly when embedding large or complex specimens.
Likely causes
- Inadequate infiltration of paraffin
- Rapid cooling of the embedding mold
- Improper orientation of the tissue sample
- Insufficient vacuum during embedding
Immediate checks
- Check for proper paraffin temperature
- Inspect the embedding mold for cleanliness
- Ensure the tissue is adequately infiltrated with paraffin
Corrective action
- Re-embed the specimen using proper technique
- Use a vacuum to remove air bubbles during embedding
- Allow paraffin to cool slowly
Preventive action
- Maintain proper paraffin temperature during embedding
- Use a vacuum embedding system
- Ensure thorough infiltration prior to embedding
This atlas is for educational purposes for laboratory professionals. It does not replace your institutional SOPs, manufacturer instructions, validated protocols or pathologist judgment. Adapt any action to your laboratory and equipment.
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